Troopers from the barracks near Uniontown have yet to release the man's name, but say he was found dead of a single gunshot wound to the chest just before noon Wednesday.
Police believe the man drove to the barracks, got out and shot himself in the chest. His body was discovered by a trooper entering the building.
Less than a week earlier a man fatally shot himself in the parking lot of a state police barracks in Falls Creek, Jefferson County.
Suicides outside police stations are not unusual, because some victims want their bodies to be discovered by police instead of family members.